1. Field of the Invention
The present invention is related to computer network systems, and more particularly, to a system and method for establishing and maintaining network connections on clustered systems.
2. Background Information
High Availability (HA) clusters are designed to maximize availability of network services. They consist of a cluster of computer systems, each of which is called a node, in which various network streams such as a Transfer Control Protocol (TCP) connection are assigned to different nodes when one or more nodes in the cluster are not functional, or to share the network load across multiple nodes.
Early HA clusters operated in an Active/Standby mode, in which only one node was active at any given time, and network state and traffic would be redirected to the functioning node in case of a failure on one node. HA clusters are now more complex and capable of supporting multiple active nodes with load sharing across multiple nodes. In one embodiment, the cluster nodes are Stateful Inspection firewalls. Each node in a Stateful Inspection firewall cluster must maintain status on the network streams (such as a TCP connection) assigned to it for the life of the stream. This requires that once a stream is assigned to a node in the cluster, it must remain on that node for its duration.
What is needed is a system and method for directing a network stream to a node in the cluster and for ensuring that the same network stream assigned to an active node remains on that node as it traverses the network through the cluster.